Forming fastening projections on rigid substrates

ABSTRACT

Rigid substrates having molded fastener projections, and methods of making the same are disclosed. A substrate has a beam stiffness, measured as a product of an overall moment of inertia of a nominal transverse cross-section and an effective modulus of elasticity of a material from which the substrate is made, that is greater than about 200 lb-in 2  (0.574 N-m 2 ). In situ lamination of hook, bands or islands on surfaces of a rigid substrate held in a planar orientation or presenting a planar surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 11/082,384,filed Mar. 17, 2005 now abandoned. This application is also acontinuation-in-part of U.S. Ser. No. 11/005,185, filed Dec. 6, 2004 nowU.S. Pat. No. 7,727,440; which is a divisional of Ser. No. 10/163,169filed Jun. 4, 2002, now U.S. Pat. No. 6,991,843; which in turn is acontinuation-in-part of U.S. Ser. No. 09/808,395, filed Mar. 14, 2001,now U.S. Pat. No. 7,048,818, which application claims the benefit ofpriority from the following U.S. Provisional Applications Ser. No.60/242,877, filed Oct. 24, 2000 and 60/189,125, filed Mar. 14, 2000. Theentire contents of each of the foregoing are hereby incorporated byreference.

TECHNICAL FIELD

This invention relates to rigid substrates having molded fastenerprojections, and methods of making the same.

BACKGROUND

Early male touch fastener products were generally woven materials, withhooks formed by cutting filament loops. More recently, arrays of smallerfastener elements have been formed by molding the fastener elements, orat least the stems of the elements, of resin, forming an interconnectsheet of material. Generally, molded plastic hook tape has displacedtraditional woven fabric fasteners for many applications, primarilybecause of lower production costs.

Molded plastic hook tape is often attached to substrates by employing anadhesive, or by sewing when the substrate is a made from sewablematerial. Often, adhesive-backed hook tape is utilized to attach thehook tape at desired locations on the substrate. Unfortunately, theprocess of applying adhesive-backed hook tape can be slow, and adhesionof the adhesive-backed hook tape to the substrate can be poor.

SUMMARY

Generally, the invention relates to rigid substrates having moldedfastener projections, e.g., hooks or stems from which fastener elementscan be formed, and methods of making the same.

In one aspect, the invention features a method of molding projections ona substrate. The method includes introducing a substrate having an outersurface into a gap formed between a peripheral surface of a rotatingmold roll that defines a plurality of discrete cavities that extendinwardly from the peripheral surface, and a supporting surface. Resin isdelivered to a nip formed between the outer surface of the substrate andthe peripheral surface of the rotating mold roll. The outer surface ofthe substrate and the peripheral surface of the rotating mold roll arearranged to generate sufficient pressure to at least partially fill thecavities in the mold roll as the substrate is moved through the gap tomold an array of discrete projections including stems that extendintegrally from a layer of the resin bonded to the substrate. The moldedprojections are then withdrawn from their respective cavities byseparation of the peripheral surface of the mold roll from the outersurface of the substrate by continued rotation of the mold roll. Thesubstrate has a beam stiffness, measured as a product of an overallmoment of inertia of a nominal transverse cross-section and an effectivemodulus of elasticity of a material from which the substrate is formed,that is greater than about 200 lb-in² (0.574 N-m²).

In some embodiments, the beam stiffness is greater than 1,000 lb-in²(2.87 N-m²), e.g., 4,000 lb-in² (11.48 N-m²) or more, e.g., 8,000 lb-in²(22.96 N-m²).

In some instances, the effective modulus of elasticity of the materialfrom which the substrate is formed is greater than 100,000 psi (6.89×10⁸N/m²), e.g., 250,000 psi (1.72×10⁹ N/m²), 750,000 psi (5.17×10⁹ N/m²),1,000,000 psi (6.89×10⁹ N/m²) or more, e.g., 5,000,000 psi (3.45×10¹⁰N/m²), 15,000,000 psi (1.03×10¹¹ N/m²) or more, e.g., 30,000,000 psi(2.07×10¹¹ N/m²).

In some implementations, the supporting surface is a peripheral surfaceof a counter-rotating pressure roll or a fixed pressure platen.

In some embodiments, the cavities of the mold roll are shaped to moldhooks so as to be engageable with loops. In other embodiments, thecavities of the mold roll are shaped to mold hooks, and the hooks arereformed after molding.

In some instances, each projection defines a tip portion, and the methodfurther includes deforming the tip portion of a plurality of projectionsto form engaging heads shaped to be engageable with loops, or otherprojections, e.g., of a complementary substrate.

In some embodiments, the resin is delivered directly to the nip. In someimplementations, the resin is delivered first to the outer surface ofthe substrate upstream of the nip, and then the resin is transferred tothe nip, e.g., by rotation of the mold roll.

The substrates can have a variety of shapes, e.g., the substrate canhave an “L” shape, “T” shape or “U” shape in transverse cross-section.

In some embodiments, the method further includes introducing anotherresin beneath the resin such that the other resin becomes bonded to theouter surface of the substrate and the resin becomes bonded to an outersurface of the other resin.

The substrate can have, e.g., an average surface roughness of greaterthan 1 micron, e.g., 2 micron, 4 micron, 8 micron, 12 micron or more,e.g., 25 micron.

In some implementations, the substrate is formed from more than a singlematerial.

In some instances, the projections have a density of greater than 300projections/in² (46.5 projections/cm²).

In some embodiments, the method further comprises pre-heating thesubstrate prior to introducing the substrate into the gap, or primingthe substrate prior to introducing the substrate into the gap.

In another aspect, the invention features a method of moldingprojections on a substrate. The method includes introducing a substrate,e.g., a linear substrate, having an outer surface into a gap formedbetween a peripheral surface of a rotating mold roll that defines aplurality of discrete cavities that extend inwardly from the peripheralsurface, and a supporting surface. The resin is delivered to a nipformed between the outer surface of the substrate and the peripheralsurface of the rotating mold roll. The outer surface of the substrateand the peripheral surface of the rotating mold roll are arranged togenerate sufficient pressure to at least partially fill the cavities inthe mold roll as the substrate is moved through the gap to mold an arrayto discrete projections including stems extending integrally from alayer of the resin bonded to the substrate. The molded projections arewithdrawn from their respective cavities by separation of the peripheralsurface of the mold roll from the outer surface of the substrate bycontinued rotation of the mold roll. The substrate has a beam stiffnesssufficiently great that during withdrawal of the molded projections fromtheir respective cavities, the substrate remains substantially linear.

In some embodiments, the beam stiffness of the substrate, measured as aproduct of an overall moment of inertia of a nominal transversecross-section and an effective modulus of elasticity of material of thesubstrate, is greater than about 200 lb-in² (0.574 N-m²).

In another aspect, the invention features an article having moldedfastening projections. The article includes a substrate and an array ofdiscrete molded projections including stems extending outwardly from andintegrally with a molded layer of resin solidified about surfacefeatures of the substrate, and thereby securing the projections directlyto the substrate. The substrate has a beam stiffness, measured as aproduct of an overall moment of inertia of a nominal transversecross-section and an effective modulus of elasticity of a material fromwhich the substrate is made, that is greater than about 200 lb-in²(0.574 N-m²).

In some embodiments, the beam stiffness is greater than about 1,000lb-in² (2.87 N-m²), e.g., 4,000 lb-in² (11.48 N-m²).

Embodiments may have one or more of the following advantages.Projections can be integrally molded onto substrates, e.g., substratesuseful in construction, e.g., wallboard, window frames, panels, ortiles, without the need for using an adhesive, often reducingmanufacturing costs, e.g., by reducing labor costs and increasingthroughput. Integrally molding projections often improves adhesion ofthe molded projections to the substrate and reduces the likelihood ofdelamination of the molded projections from the substrate during theapplication of a force, e.g., a peeling force, or a shear force.

In situ lamination of hook, bands or islands on rigid materials held ina planar orientation or presenting a planar surface, extend in rigidflexible materials is also featured.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference herein to their entirety.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a process for molding hooks onto a T-shapedsubstrate, the process utilizing a fixed pressure platen as a supportingsurface for the T-shaped substrate.

FIG. 1A is a cross-sectional view taken along 1A-1A of FIG. 1.

FIG. 1B is an enlarged side view of Area 1B of FIG. 1.

FIG. 1C is a cross-sectional view taken along 1C-1C of FIG. 1.

FIG. 2 is a side view of an alternative process for molding hooks onto asubstrate, the process utilizing a counter-rotating pressure roll assupport for the substrate.

FIG. 2A is an enlarged side view of a reforming roll (Area 2A) of FIG.2.

FIG. 3 is a side view of a process for molding stems onto a substrate.

FIG. 3A is an enlarged side view of Area 3A of FIG. 3, showing asubstrate having molded stems.

FIG. 4 is a side view of a process for reforming the molded stems ofFIG. 3 to form engageable projections shaped to be engageable with loops(FIG. 4B) or other projections.

FIG. 4A is an enlarged side view of Area 4A of FIG. 4.

FIG. 4B is an enlarged cross-sectional view of a substrate carryingfibrous loops.

FIG. 4C is a side view of two substrates having deformed molded stems,illustrating how the two substrates can engage each other.

FIG. 5 is a side view of a process for molding hooks onto a substratethat utilizes a tie layer.

FIG. 5A is an enlarged side view of Area 5A of FIG. 5.

FIGS. 6 and 7 are cross-sectional views of planar, laminated substrates,having two and three layers, respectively.

FIG. 8 is a cross-sectional view of an L-shaped substrate having hooksin which heads are directed in a single direction, and FIG. 8B is aperspective view of the L-shaped substrate of FIG. 8A.

FIG. 9 is cross-sectional view a U-shaped substrate having moldedprojections.

FIG. 10 is a front view of a fastener element molding apparatus of thepresent invention applying fastener elements to a planar sheet or workpiece.

FIG. 11 is an isometric view of the apparatus of FIG. 10 illustratingonly the fastener element mold roll portion of the apparatus applyingengageable fastener elements to a sheet or work piece.

FIG. 12 is a cross-sectional view of the mold roll in FIG. 11 takenalong line 12-12 of FIG. 11.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Rigid substrates having molded fastener projections, and methods ofmaking the same are described herein. Generally, the substrates have abeam stiffness that is sufficiently great such that during withdrawal ofthe molded projections from their respective cavities, the substrateremains substantially straight, and does not bend away from its support.

Referring collectively to FIGS. 1 and 1A-1C, a process 10 for integrallymolding projections, e.g., hooks 12, onto a substrate 14, e.g., aT-shaped substrate, includes introducing the substrate 14 that has anouter surface 16 into a gap 18 formed between a peripheral surface 20 ofa rotating mold roll 22 and a fixed pressure platen 24 that has asupporting surface 27. The mold roll 22 defines a plurality of discretecavities, e.g., cavities 26 in the shape of hooks, that extend inwardlyfrom peripheral surface 20 of the rotating mold roll 22. An extruder(not shown) pumps resin 30, e.g., molten thermoplastic resin, through adie 31 where it is delivered to a nip N formed between outer surface 16of the substrate and peripheral surface 20 of the rotating mold roll 22.The outer surface 16 of the substrate 14 and peripheral surface 20 ofrotating mold roll 22 are arranged to generate sufficient pressure tofill the cavities in the mold roll 22 as substrate 14 is moved throughgap 18 to integrally mold an array of discrete hooks 12, including stems34, which extend outwardly from and are integral with a layer 40 that isbonded to outer surface 16. The molded hooks 12 are withdrawn from theirrespective cavities 26 by separation of the peripheral surface 20 of themold roll 22 from outer surface 16 of substrate 14 by continued rotationof mold roll 22. Substrate 14 has a beam stiffness sufficiently greatsuch that during withdrawal of hooks 12 from their respective cavities,the substrate 14 remains substantially linear, and is not bent away fromthe supporting surface 27 of fixed pressure platen 24 toward moll roll22 (indicated by arrow 29). For example, substrate 14 has a beamstiffness, measured as a product of an overall moment of inertia of anominal transverse cross-section and an effective modulus of elasticity(Young's modulus) of a material from which the substrate is formed, thatis, e.g., greater than 1,000 lb-in² (2.87 N-m²), e.g., 4,000 lb-in²(11.48 N-m²) or greater, e.g., 8,000 lb-in² (22.96 N-m²). The effectivemodulus of elasticity of the material from which the substrate is formedis measured using ASTM E111-04 at 25° C. at fifty percent relativehumidity, allowing sufficient time for moisture and temperatureequilibration.

In some implementations, the outer surface 16 of substrate 14, theperipheral surface 20 of the rotating mold roll 22 and the resin 30 arearranged to generate sufficient friction such that the substrate 14 ispulled into and moved through gap 18, in a direction indicated by arrow41, by continued rotation of mold roll 22.

In some embodiments, mold roll 22 includes a face-to-face assembly ofthin, circular plates or rings (not shown) that are, e.g., about 0.003inch to about 0.250 inch (0.0762 mm-6.35 mm) thick, some rings havingcutouts in their periphery that define mold cavities, and other ringshaving solid circumstances, serving to close the open sides of the moldcavities and to serve as spacers, defining the spacing between adjacentprojections. In some embodiments, adjacent rings are configured to moldhooks 12 such that alternate rows 50, 52 (FIG. 1B) have oppositelydirected heads. A fully “built up” mold roll may have a width, e.g.,from about 0.75 inch to about 24 inches (1.91 cm-61.0 cm) or more andmay contain, e.g., from about 50 to 5000 or more individual rings.Further details regarding mold tooling are described by Fisher, U.S.Pat. No. 4,775,310, the disclosure of which is hereby incorporated byreference herein in its entirety.

Referring to FIG. 2, in an alternative embodiment, the supportingsurface for substrate 14 is a peripheral surface 54 of acounter-rotating pressure roll 56. As discussed above, an extruder (notshown) pumps resin through die 31 and delivers the resin 30 to nip N tomold an array of discreet hooks 12 extending integrally from layer 40that is bonded to the substrate. While an extruder (not shown) can pumpresin 30 directly into the nip N, other points of delivery are possible.For example, as shown in FIG. 2, rather than delivering resin directlyto nip N, extruder die 31 can be positioned to deliver resin 30 first tothe outer surface 16 of substrate 14 upstream of the nip N. In thisembodiment, resin 30 is transferred to nip N by moving substrate 14through gap 18. This can be advantageous, e.g., when it is desirablethat the resin 30 be somewhat set, e.g., cooled, prior to entering thenip N. In other embodiments, also as shown in FIG. 2, extruder die 31 ispositioned to deliver resin 30 first to the outer surface 20 of therotating mold roll 22. In this implementation, resin 30 is transferredto the nip N by rotating of the mold roll 22.

Referring particularly to FIG. 2A, in some instances, hooks 71 remainslightly deformed after being withdrawn from their respective cavitiesduring separation of the peripheral surface 20 from the outer surface 16of substrate 14. To return these hooks to their as-molded shape, theprocess shown in FIG. 2 can optionally include a reforming roll 70 thatreforms deformed hooks 71 with pressure and, optionally, heat as themolded hooks move below the reforming roll 70. In some instances, it isdesirable that the reforming roll 70 be rotated such that it has atangential velocity that is higher than, e.g., ten percent higher ormore, e.g., twenty-five percent higher, than the velocity of thesubstrate 14 to aid in the reforming of the deformed hooks. In someinstances, reforming roll 70 can be used to maintain substrate 14 in asubstantially linear state, by hindering movement of substrate 14 towardthe mold roll.

In some embodiments, the process shown in FIG. 2 can optionally includea counter rotating nip-roller 74 in conjunction with the reforming roll70 to aid in the moving of substrate 14 through gap 18.

Referring now to FIGS. 3 and 3A, in an alternative embodiment, a process90 for integrally molding projections in the shape of stems 82 ontosubstrates includes a mold roll 22 that defines a plurality of discretecavities 80 in the shape of stems 82 that extend inwardly from aperipheral surface 20 of the rotating mold roll 22. In some instances,removal of molded projections that are in the shape of stems 82 from amold roll can be easier (relative to projections in the shape of hooks)because the mold roll does not have cavities that have substantialundercuts. As a result, substrate 14 can often have a lower beamstiffness (relative to embodiments of FIGS. 1 and 2) and still remainsubstantially linear during withdrawal of the stems 82 from theirrespective cavities 80. For example, the substrate can have a beamstiffness that is, e.g., greater than 200 lb-in² (0.574 N-m²), e.g.,1,000 lb-in² (2.87 N-m²).

Referring to FIGS. 4-4C, the projections in the shape of stems 82 thatwere integrally molded to substrate 14 by the process shown in FIG. 3can be deformed (such as when a thermoformable resin is employed to moldthe stems) by a deforming process 100. Process 100 can form engagingheads 102 shaped to be engageable with loops 103 that extend from a base104 of a mating material (FIG. 4B), or that are engageable with otherprojections 102′ of a mating substrate 106 (FIG. 4C).

Referring particularly to FIG. 4, a heating device 110 includes a heatsource 111, e.g., a non-contact heat source, e.g., a flame, anelectrically heated wire, or radiant heat blocks, that is capable ofquickly elevating the temperature of material that is close to heatsource 111, without significantly raising the temperature of materialthat is further away from heat source 111. After heating the stems 82,the substrate moves to conformation station 112, passing betweenconformation roll 114 and drive roll 116. Conformation roll 114 deformsstems 82 to form engageable heads 102, while drive roll 116 helps toadvance the substrate.

It is often desirable to chill the conformation roll, e.g., by runningcold water through a channel 115 in the center of roll 114, tocounteract heating of conformation roll 114 by the heat of the resin.Process 100 can be performed in line with the process shown in FIG. 3,or it can be performed as a separate process. Further details regardingthis deforming process are described by Clarner, U.S. patent applicationSer. No. 10/890,010, filed Jul. 13, 2004, the entire contents of whichare incorporated by reference herein.

Referring now to FIGS. 5 and 5A, in an alternative embodiment, asextruder (not shown) pumps resin 30 through die 31, and delivers resin30 to nip N formed between outer surface 16 of substrate 14 andperipheral surface 20 of rotating mold roll 22. At the same time, asecond extruder (not shown) pumps another resin 152 through another die150, and delivers the other resin to the nip N such that the other resin152 is disposed underneath the resin 30, becoming bonded to the othersurface 16 of substrate 14 (formed layer 160, e.g., a tie layer), whilethe resin 30 becomes bonded to an outer surface of the other resin 152.This is often advantageous, e.g., when adhesion of resin 30 to surface16 is poor. In some embodiments, a maleated polypropylene, or a blend ofmaleated polypropylene and polypropylene is used a other resin 152, andpolypropylene is used as resin 30.

In any of the above embodiments, suitable materials for formingprojections e.g., hooks 12 or stems 82, are resins, e.g., thermoplasticresins, that provide the mechanical properties that are desired for aparticular application. Suitable thermoplastic resins includepolypropylene, polyethylene, acrylonitrile-butadiene-styrene copolymer(ABS), polyamide, e.g., nylon 6 or nylon 66, polyesters, e.g.,polyethylene terephthalate (PET) or polybutylene terephthalate (PBT),and blends of these materials. The resin may include additives, e.g.,lubricating agents, e.g., silicones or fluoropolymers, solid fillers,e.g., inorganic fillers, e.g., silica or pigments, e.g., titaniumdioxide. In some embodiments, lubricating agents are employed to reducethe force required to remove molded hooks from their respectivecavities. In some embodiments, an additive is used to improve adhesionof the resin 30 to substrate 14, e.g., an anyhydride-modified linearlow-density polyethylene, e.g., Plexar® PX114 available from Quantum.

In any of the above embodiments, the overall moment of inertia of thenominal transverse cross-section of the substrate can be greater than0.00020 in⁴ (0.00832 cm⁴). Examples of substrate inertial momentsinclude 0.00065 in⁴ (0.0271 cm⁴), 0.0050 in⁴ (0.208 cm⁴), 0.040 in⁴(1.67 cm⁴) and 0.5 in⁴ (20.8 cm⁴).

In any of the above embodiments, the effective modulus of elasticity ofthe material from which the substrate can be greater than 100,000 psi(6.89×10⁸ N/m²), e.g., 250,000 psi (1.72×10⁹ N/m²), 750,000 psi(5.17×10⁹ N/m²), 1,000,000 psi (6.89×10⁹ N/m²) or more, e.g., 5,000,000psi (3.45×10¹⁰ N/m²), 15,000,000 psi (1.03×10¹¹ N/m²) or more, e.g.,30,000,000 psi (2.07×10¹¹ N/m²). The effective modulus of elasticity ofthe material from which the substrate is formed is measured using ASTME111-04 at 25° C. at fifty percent relative humidity, allowingsufficient time for moisture and temperature equilibration.

In any of the above embodiments, the substrate can be, e.g., aconstruction material, such as wallboard, window frame, wall panel,floor tile, or ceiling tile.

In any of the above embodiments, in order to improve adhesion of resinto the substrate, it is often advantageous to mold onto a substrate withan average surface roughness of greater than 1 micron, e.g., 2, 3, 4, 5micron or more, e.g., 10 micron, as measured using ISO 4288:1996(E).

In any of the above embodiments, the projections, e.g., hooks 12 orstems 82, preferably have a density of greater than 300 projections/in²(46.5 projections/cm²), e.g., 500 (77.5 projections/cm²), 1,000 (155.0projections/cm²), 2000 (310.0 projections/cm²) or more, e.g., 3,500projections/in² (542.5 projections/cm²).

In any of the above embodiments, the substrate can be pre-heated priorto introducing substrate 14 into the gap 18. Pre-heating is sometimesadvantageously used to improve adhesion of the resin 30 (or other resin152) to substrate 14. It can also be used, when a thermoplastic resin isemployed, to prevent over cooling of the thermoplastic resin beforeentering the nip N.

In any of the above embodiments, substrate 14 can be primed, e.g., toimprove the adhesion of resin 30 (or 152) to substrate 14. In someembodiments, the priming is performed just prior to introducing ofsubstrate 14 into the gap 18. Suitable primers include acetone,isobutane, isopropyl alcohol, 2-mercaptobenziothiazole, N,N-dialkanoltoluidine, and mixtures of these materials. Commercial primers areavailable from Loctite® Corporation, e.g., Loctite® T7471 primer.

While certain embodiments have been described, other embodiments areenvision.

While various locations of an extruder head are specifically shown inFIG. 2, these locations can be applied to any of the embodimentsdescribed above.

As another example, while embodiments have been described in whichsubstrates are formed from a single material, in other embodiments,substrates are formed from multiple materials. For example, thesubstrates can be formed of wood, metal, e.g., steel, brass, aluminum,aluminum alloys, or iron, plastic, e.g., polyimide, polysulfone, orcomposites, e.g., composites of fiber and resin, e.g., fiberglass andresin.

As an additional example, while embodiments have been described in whichthe base of the fastener is formed of a single layer, in otherembodiments, such bases are formed of more than a single layer ofmaterial. Referring to FIGS. 6 and 7, a fastener base bonded to a rigidsubstrate may be formed of two layers 172 and 174 (FIG. 6), and eachlayer can be a different kind of resin. In still other embodiments, asubstrate may be formed of three layers 182, 184 and 186 (FIG. 7). Morethan three layers are possible.

As a further example, while substrates have been described that areT-shaped and planar in transverse cross-section, other transverse shapesare possible. Referring to FIGS. 8A and 8B, an L-shaped substrate havinghooks in which heads are directed in a single direction is shown. Stillother shapes are possible. For example, FIG. 9 shows a U-shapedsubstrate.

While the embodiments of FIGS. 1-3 show resin being continuouslydelivered to nip N, in some instances it is desirable to deliverdiscrete doses or charges of resin to the substrate, e.g., to reduceresin costs, so that projections are arranged on only discrete areas ofthe substrate. This can be done, e.g., by delivering the doses orcharges through an orifice defined in an outer surface of a rotating diewheel, as described in “Delivering Resin For Forming Fastener Products,”filed Mar. 18, 2004 and assigned U.S. Ser. No. 10/803,682, the entirecontents of which are incorporated by reference herein.

While projections 82 of FIG. 3A are shown to have radiused terminalends, in some embodiments, projections have non-radiused, e.g.,castellated terminal ends, such as some of the projections described in“HOOK AND LOOP FASTENER,” U.S. Ser. No. 10/455,240, filed Jun. 4, 2003,the entire contents of which are incorporated by reference herein.

Referring to FIGS. 10, 11 and 12 substrate 14 is of planar form as itproceeds through the mold station. As shown in FIG. 10, acantilever-mounted mold roll 46 a extends inwardly form the edge ofsubstrate 14 or the work piece to the position where a band or bands ofmolded fastener stems or fully formed molded fastener hooks, aredesired.

Where the band or bands of fastener stems or fully formed hooks are tobe applied near the edge of substrate 14, the required nip forces aresufficiently low that rolls 46 a and 48 a may be supported from one endusing suitably spaced bearings of a cantilever mounting. Thatarrangement is suggested in the solid line diagram of the mounting ofmold roll 46 a in FIG. 10. Where the nip pressure is greater, acantilever support 35 for a second bearing is employed, as suggested indashed lines in the figure.

Referring to FIGS. 10 and 11, the operation of a molding apparatus isillustrated with substrate 14 being fed through nip N formed by moldroll 46 a and pressure roll 48 a. Mold roll 46 a extends from frame 36in a cantilevered fashion, e.g., supported from one side only, so thatsubstrate 14 of width, W₂, greater than the width, W₃, of mold roll 46 acan be processed through nip N without interfering with frame 36.Typically mold roll 46 has width W₃ of less than approximately 2 ft. Thecantilevered support of one of the rolls leaves an open end of nip N toallow workpieces of substantially greater than either roll 46 a or 48 ato pass through nip N without interfering with support frame 36. Assubstrate 14 moves through nip N, cavities 37 of mold roll 46 a arefilled, as described below, with molten thermoplastic resin, e.g.,polypropylene, to form engageable elements, e.g., hooks which aredeposited in a relatively narrow band onto a portion of substrate 14.The initially molten thermoplastic resin adheres the base of each hookstem to substrate 14 as the thermoplastic resin solidifies, in an insitu bonding action.

The amount of molten thermoplastic resin delivered to the mold rolldetermines whether the hooks will form an integral array ofthermoplastic resin joined together by a thin base layer which isadhered to the surface of the preformed carrier sheet or substrate 14 orwhether the hooks will be separate from one anther, individually adheredto the carrier. For example, as shown in FIG. 4A, a thin layer ofthermoplastic resin forms the base layer 40, which is integral with thearray of fastener projections extending therefrom.

However, by reducing the amount of thermoplastic resin delivered to themold roll, joining base layer 122 a can be eliminated so that the baseof each molded fastener stem is in situ bounded substrate 14 withoutthermoplastic resin joining hooks 124 c together.

Referring now to FIG. 12, an example of delivery of molten thermoplasticresin to the mold roll 46 a to form fastener elements 124 c on substrate14 will be described. Molten thermoplastic resin is delivered to moldroll 46 a by extruder 42. Delivery head 42 a of extruder 42 is shaped toconform with a portion of the periphery of mold roll 46 a to form baselayer 122 a and to prevent extruded thermoplastic resin from escaping asit is forced into hook cavities 37 of rotating (counterclockwise) moldroll 46 a. Rotation of mold roll 46 a brings base portions ofthermoplastic resin-filled cavities 37 into contact with substrate 14and the thermoplastic resin is forced (by pressure roll 48 a (FIG. 10))to bond to the surface of substrate 14. In the case of porous or fibroussubstrates, carrier sheets or workpieces, the thermoplastic resinsolidifies, portions which have partially penetrated the surface adhereto substrate 14 with further rotation of mold roll 46 a partiallysolidified molded hooks 124 c or stems are extracted from mold cavities37 leaving a band of hooks or stems projecting from substrate 14. Byadjusting the space between head 42 a and mold 46, the volume of moltenthermoplastic resin delivered, and the speed rotation of mold roll 46 a,an amount of thermoplastic resin beyond the capacity of mold cavities 37can be delivered to mold roll 46 a. This additional thermoplastic resinresides on the periphery of mold roll 46 a and is brought into contactwith substrate 14 to form base layer 122 a of thermoplastic resin fromwhich the stems of the engaging elements 124 c extend. In dashed lines,an alternative method of delivering the molten resin to the mold roll,as described previously above, is also suggested.

It will be realized that the apparatus of FIGS. 10-12 do not requirethat substrate 14 be flexible. It may indeed be a rigid workpiece, forinstances it may be a construction material such as performed buildingsiding, roofing material, or a structural member, fed through themolding station on appropriate conveyors. The apparatus of all of theembodiments may be incorporated in a manufacturing line, in which thesubstrate, carrier or workpiece is a perform, upon which further actionsare taken other than in situ bonding of fasteners or fastener stemsoccurs. The manufacturing line may be, e.g., for manufacture of buildingsiding, roof shingles or packaging sheet or film.

There are other ways to form e.g. separated parallel linear bands ordiscrete, disconnected islands of hooks on the above-describedsubstrates within certain broad aspects of the present invention. Forexample, at dispersed, selected locations across the width of atraveling preformed substrate, e.g. a material defining hook-engageableloops, discrete separate molten resin deposits of the desired form, e.g.of x, y-isolated islands, or in spaced apart parallel bands, may bedeposited upon the surface structure of the substrate. Following this,upper portions of the resin deposits, while still molten, or after beingreheated by an intense localized flame line, are molded into fastenerstems by mold cavities that are pressed against the resin deposits. Forinstance, at selected widthwise separated locations along a depositline, as the substrate transits the line, discrete island-form depositsare made at selected locations. Immediately, with the resin stillmolten, or after heat activation, the substrate is introduced into amolding nip, formed by a mold roll and a pressure roll. The mold roll,for instance, defines tiny fixed hook fastener cavities as describedabove, or smaller fastener features, e.g. of less than 0.005 inchheight, or similarly shallow cavities for tiny stem preforms, that arealigned to press down upon the resin deposits under conditions in whichnip pressure causes the molten resin to enter the cavities at the baseof the stem portion of the cavities, and fill the molds, and be moldedinto a localized dense array of stem preforms or into a localized densearray of fully formed loop-engageable molded hooks. With appropriateamounts of resin in the deposits, a base layer common to all of themolded sterns of a discrete island deposit can be formed by the moldroll surface, as may be desired. The mold pressure, simultaneously withthe molding, causes the resin to bond firmly to the surface structure ofthe preformed carrier, effecting in situ lamination. Where the preformedsubstrate has a fibrous or porous makeup, as with hook-engageable loopmaterial, the nip pressure causes the resin to comingle with the topfibers or other structure that define the surface structure of thesubstrate, without penetrating the full depth of the substrate. Thus theopposite side of the substrate can remain pristine, free of the moldingresin, and, if the opposite surface of the preformed web defines auniform surface of hook-engageable loops across the full width of thearticle, the effectiveness of those loops can be preserved while themolded stems or fully molded hooks are molded and in situ bondingoccurs.

With such arrangements it will be understood that the regions of thesubstrate between the separated islands remain free of the resin fromwhich the hooks or stem preforms are molded. Thus, in the case ofelastically stretchy substrate webs or carrier sheet preforms, whetherof plain preformed elastomer sheet, or a stretchy hook-engageable loopmaterial, the resin-free regions enable the web to be elasticallystretchy, while flexibility of the article in both orthogonal (X, Y)directions in the plane of the web is achieved. Where the preformedcarrier web is a non-stretchy, but flexible material, such as abi-directionally stabilized knit loop product having hook-engageableloops on both sides, the regions between the separated islands enablethe finished article to be simply flexible in both X and Y directions inthe plane of the fabric.

In certain embodiments, rather than locating discrete regions of hookcavities on the mold roll, in positions to register with a pre-arrangedpattern of resin deposits, the mold roll may simply have an array ofmold cavities entirely occupying the mold surface of the roll, or mayhave such mold cavities in narrow bands separated by enlarged spacerrings or cross-wise extending ridges, as described above.

Still other embodiments are within the scope of the claims that follow.

1. A method of forming fastening projections on a rigid substrate, themethod comprising: delivering a resin to an outer surface of a rigidsubstrate; molding from the resin an array of discrete stems in cavitiesdefined in a peripheral surface of a mold roll rolled over the surfaceof the substrate, the stems withdrawing from their cavities bycontinuous rotation of the mold roll while the substrate remains rigid,leaving the stems projecting from the surface of the substrate; bondingthe resin to the outer surface of the substrate; and forming fasteningheads at distal ends of the stems, wherein the substrate comprises oneor more members selected from the group consisting of a wallboard, awindow frame, a wall panel, a floor tile, and a ceiling tile.
 2. Themethod of claim 1, wherein the molding and bonding comprise generatingsufficient pressure between the substrate and the mold roll to at leastpartially fill the cavities in the mold roll with the resin whilebonding the resin to the substrate.
 3. The method of claim 2, whereinthe discrete projecting stems are molded to extend integrally from acommon layer of the resin bonded to the substrate.
 4. The method ofclaim 2, wherein the resin penetrates the surface of the substratethrough pores or fiber interstices in the surface of the substrate. 5.The method of claim 1, wherein the resin is delivered and the arraybonded so as to form a discrete band or island of projections on thesubstrate.
 6. The method of claim 1, wherein the cavities are shaped toform the fastening heads on the stems as the stems are molded, thefastening heads deforming as they are withdrawn from the cavities. 7.The method of claim 1, wherein the resin is delivered to the substrateby the mold roll.
 8. The method of claim 1, comprising introducing thesubstrate to a gap defined between the mold roll and a counter-rotatingpressure roll.
 9. The method of claim 8, wherein the pressure roll orthe mold roll defines a groove to accommodate a shape of the substrate.10. The method of claim 8, wherein the mold roll and pressure roll areinterconnected on one side of the gap, with an opposite side of the gapopen for accommodating wide substrates, the method forming fastenerprojections along an edge region of the substrate while an opposite edgeof the substrate extends beyond the mold roll.
 11. The method of claim1, comprising selecting whether the discrete projections are bondeddirectly to the surface of the substrate or whether the discreteprojections extend integrally from a layer of resin bonded to thesurface of the substrate and then choosing an amount of resin to bedelivered in consideration of such selection.
 12. The method of claim 1,wherein the substrate comprises rigid building material.
 13. The methodof claim 1, further comprising heating the resin between delivering theresin and one of the molding and bonding steps.
 14. The method of claim1, where the resin is delivered into a nip formed between the mold rolland the substrate.
 15. The method of claim 1, wherein a pre-arrangedpattern of resin is delivered to be aligned with a pre-arranged patternof cavities in the mold roll.
 16. The method of claim 1, wherein theresin is delivered to form separated array bands of projections and theresin is molded into the separated array bands by a continuous patternof cavities in the mold roll.
 17. The method of claim 1, wherein thediscrete projections are molded in the form of hooks.
 18. The method ofclaim 1, wherein the resin is delivered directly into the cavities inthe mold roll and the resin is then bonded to the substrate.
 19. Themethod of claim 18, comprising delivering additional resin to theperipheral surface of the mold roll to form a base layer, such that thediscrete projections extend integrally from the base layer of resinwhich is bonded to the substrate.
 20. The method of claim 18 wherein thediscrete projections are individually bonded to the surface of thesubstrate without any additional resin bonded between the projections tothe surface of the substrate.
 21. The method of claim 1, wherein theresin is delivered to the substrate before filling the cavities of themold roll.
 22. The method of claim 1, wherein the molding and bondingoccur simultaneously in response to pressure between the mold roll andthe substrate surface.
 23. The method of claim 1, wherein the substratehas a beam stiffness, measured as a product of an overall moment ofinertia of a nominal cross-section of the substrate and an effectivemodulus of elasticity of a material from which the substrate is formed,that is greater than about 200 lb-in².
 24. The method of claim 23,wherein the beam stiffness is greater than 1,000 lb-in².
 25. The methodof claim 1, wherein the method comprises passing the substrate through anip defined between the mold roll and a pressure roll and introducingthe resin into the nip, wherein a portion of the substrate extendslaterally beyond the mold roll when the substrate is passed through thenip.
 26. The method of claim 25, wherein the mold roll has first andsecond end portions and the pressure roll has third and fourth endportions, the first and second end portions of the mold roll and thethird and fourth end portions of the pressure roll are rotatably coupledto a frame, and the frame forms a slot through which the substrateextends when the substrate is passed through the nip such that a portionof the substrate extends laterally beyond the frame and the mold andpressure rolls as the substrate passes through the nip.
 27. The methodof claim 25, wherein the mold roll has a first end portion rotatablyattached to a frame and second end portion detached from the frame in acantilevered arrangement, and the cantilevered arrangement of the firstcylindrical roll allows the substrate to extend laterally beyond theframe and the mold roll as the substrate passes through the nip.
 28. Amethod of forming fastening projections on a rigid substrate, the methodcomprising: delivering a resin to an outer surface of a rigid substrate;molding from the resin an array of discrete stems in cavities defined ina peripheral surface of a mold roll rolled over the surface of thesubstrate, the stems withdrawing from their cavities by continuousrotation of the mold roll while the substrate remains rigid, leaving thestems projecting from the surface of the substrate; bonding the resin tothe outer surface of the substrate; and forming fastening heads atdistal ends of the stems, wherein the resin is delivered directly intothe cavities in the mold roll and the resin is then bonded to thesubstrate, and wherein the discrete projections are individually bondedto the surface of the substrate without any additional resin bondedbetween the projections to the surface of the substrate.